Disc drives are commonly used in work stations, personal computers, portable computers, and other computer systems to store large amounts of data in a form that can be made readily available to a user. In general, a disc drive comprises one or more magnetic discs that are rotated by a spindle motor at a constant high speed. A transducer is used to write and/or read back information from the surface of a disc.
Continued demand exists for higher disc drive performance from disc drives having smaller form factors. Such demands require increases in spindle motor rotation speeds, increases in areal density recording capabilities, and faster data access times, along with decreases in the size of the disc drive components and the housing that encloses them. Standard disc drives used in personal computers are formed in accordance with a one-inch form factor (height). Such standard disc drives have been essentially miniaturized to form microdrives. Such microdrives typically have a 5.0 millimeter (mm) form factor and are formed in accordance with CompactFlash® Type II specifications. One of the difficulties in meeting such a small form factor is the formation of the base of the micro drive that provides support for the components of the disc drive and which also prevents contamination from reaching the inside of the disc drive.
Disc drive bases are designed to provide the necessary structural integrity to support the mounting of internal disc drive components as well as to support attachment of the disc drive to a user environment. Typically, disc drive bases are formed from an aluminum casting or stamping process and undergo secondary machining operations as required to form the requisite critical surfaces for proper alignment of the disc drive components. Certain of the larger features on the base, such as motor and base interfaces, lend themselves to manufacturing by this stamping and secondary machining. However, other more detailed features such as the mounting slot, the filter holder and actuator crash stops are difficult to make by this process alone, especially given more stringent form factor requirements of small designs. In these designs, an overmolded plastic injection process is used to create a composite metal/plastic base. In this process, plastic is injected through entrance holes in the base and the plastic allowed to set while a mold remains in place over the base. The overmolded plastic portion of the base closely follows the surface of the metal base where intended. In some cases, however, the interface between the plastic and the metal base also permits air to flow into the disc drive. This can allow particle contamination to enter the drive housing.
To address the continued demands for ever decreasing form factors, such as the 3.3 mm form factor of CompactFlash® Type I specifications, new base designs can be employed. However, the base design should be configured to reduce entry of contaminated particles into the housing. Embodiments of the present invention provide solutions to meet such disc drive base demands while offering other advantages over bases of the prior art.
Other features and benefits that characterize embodiments of the present invention will be apparent upon reading the following detailed description and review of the associated drawings.